When engaged in activities like demolishing, abrading, or fracturing silica-containing materials such as brick, block, and concrete using heavy equipment and utility vehicles, workers need to be aware of the potential generation of respirable crystalline silica dust, which, when inhaled, can cause irreversible lung damage.
WorkCover Queensland recommends the following exposure controls in line with Appendix 4 of the Managing respirable crystalline silica in construction and manufacturing of construction elements code of practice 2022 (PDF, 1.71 MB):
Use suitable engineering controls
Consider the following engineering control options:
- Operate equipment from an enclosed cabin.
- If there are other workers outside of the cab, apply water and/or dust suppressants to minimize dust emissions.
Details of controls: Using an enclosed cab during demolition, abrading, or fracturing silica-containing materials with heavy equipment and utility vehicles helps reduce operator exposure to silica dust. When others are present, applying water and/or dust suppressants is essential to minimize visible dust.
Operator isolation:Operators using heavy equipment and utility vehicles must stay inside an enclosed cab with the doors and windows closed while work is in progress. The cab must be well-sealed, well-ventilated using positive pressure, and regularly maintained and cleaned to prevent settled dust from becoming airborne inside the enclosure. Additionally, it should have HEPA filtration fitted to the intake and cabin recirculation air intake.
Wet methods:Wet methods for operators include any wet application method that suppresses silica dust emissions and is compatible with the task. These methods involve:
- Tank trucks with hoses and nozzles spraying water or other dust suppressants over large areas.
- A worker spraying water or other types of dust suppressants on materials being demolished, abraded, or fractured.
- Spray equipment attached to the vehicle.
- Timing the application of water or other dust suppressants to ensure materials remain damp when disturbed.
Water must be applied at flow rates sufficient to minimize the release of visible dust. Too much water can create mud slurry, posing hazards, while too little water will not effectively control dust emissions.
Worker outside the cab engaged in the task:A worker assisting the operator by applying water or other types of dust suppressants to materials being demolished, abraded, or fractured.
Select appropriate respiratory protective equipment (RPE)The need for respiratory protective equipment (RPE) depends on:
- The chosen engineering controls.
- The duration of the task during the shift.
- The location of the work.
RPE is not required when using heavy equipment in an enclosed cab for tasks involving cutting, abrading, or fracturing silica-containing materials or demolition activities. However, if there are other people in the area, RPE is necessary.
| Engineering control used | Time spent doing task during shift | |
|---|---|---|
| Equal or less than 4 hours | Greater than 4 hours | |
| Operator Isolation (Option 1) | Indoors / enclosed area RPE not required | Indoors / enclosed area RPE not required |
| Indoors / enclosed area RPE not required | Indoors / enclosed area RPE not required | |
| Worker applying dust suppression (Option 2) | Outdoors P1 or P2 filtered RPE with a MPF 10 required | Outdoors P1 or P2 filtered RPE with a MPF 10 required |
| Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required | Indoors / enclosed area P1 or P2 filtered RPE with a MPF 10 required | |
Health monitoring
A person conducting a business or undertaking (PCBU) must provide health monitoring to a worker if their tasks require them to wear RPE 30 times or more in 12 months. See section 10 of the Code (PDF, 1.71 MB) for more information on health monitoring requirements.